Efforts to network together increasing numbers of electronic devices in the household or home are very well advanced. A wealth of different standards for networking devices has been formulated with partly different objectives. One of the systems provides for the devices to be networked, on the basis of the “Internet protocol” IP. There is already a first version of a standard available for this system. The system has become known by the abbreviation UPnP, which stands for Universal Plug and Play. The corresponding standard is currently available in version 1.1. More detailed information regarding the UPnP system and the associated standard can be found on the official Internet page of the UPnP consortium at www.upnp.org. The UPnP system has no restrictions regarding device types. This is intended to make it possible to network both devices from the consumer electronics field, such as TVs, DVD players, set-top boxes, video recorders, camcorders, etc., and other devices in the household, for example washing machines, refrigerators, heating controllers, coffee machines, lighting and blind controllers, alarm systems and so on. Personal computers may likewise be regarded as belonging to the category of consumer electronic devices. These are also included in the UPnP system and can be integrated into the network too.
However, the UPnP system contains no specification for the bottom layers of the OSI/ISO reference model for data communication. This relates particularly to the physical layer and the data link layer. The UPnP system therefore no longer contains a specification about what transmission medium needs to be used to transmit the data for interchange. A very wide variety of transmission standards are permissible for this. Examples of these are the Ethernet protocol, the IEEE 1394 protocol, and even wireless transmission based on IEEE 802.11x, Bluetooth or HIPERLAN/2 are likewise suitable.
The UPnP specification (see www.upnp.org) describes the structure of devices based on the UPnP standard and how to control them. One of the basic ideas of this specification is that it is possible to control any UPnP device using a standard HTML browser. To this end, every UPnP device has a web server on which the HTML pages for controlling the device (the “presentation pages”) are stored.